I've got the exact same problem.

I'm on Windows XP professional and using my laptop for development.

I've got environment variables point to a Work and Source directory

The work directory is C:\Universe\Tax

The Source directory c:\TmpSource\Tax

When I run the package through BIDS, the first task is a FileSystem Task - delete directory contents on the work directory - this is successful (although there are no files)

The next task is a file system task to copy from C:\TmpSource\Tax to C:\Universe\Tax

This files with Access to the path 'C:\tmpsource\Tax' is denied

I can browse the source directory successfully through using run

Any ideas?